Effect of Proximity between Inter Cropped Maize and Beans on Growth and Yield of Maize under Varying Nitrogen Levels

Abstract

In a field study, planting patterns of maize (Zea mays L.) and beans (Phaseolus vulgaris L.) and nitrogen fertilisation were evaluated for two seasons. Plant population of each species was 53,330 plants/ha. The planting patterns consisted of sole maize. Maize and beans intercropped in alternate rows. Maize and beans intercropped as alternate plants in the same row, and maize and beans intercropped in the same hill. The N levels were, 50, 100 and 150 kg N/ha. Yield of beans was not affected by the planting patterns. Increasing die intimacy between maize and beans increased maize biomass and yield under low N levels (0 and 60kg/ha), but had no effect at high N levels. At low N, intercropping maize and beans in the same hill out yielded all the other treatments, while intercropping in alternate rows gave the lowest yield. Increasing N application rates increased the yield of both maize and beans, but the optimal N level was lower (50 kg/ha) for maize and beans planted in the same hill Chan for monocrop maize or maize planted with beans in alternate rows (100 kg/ha). Effect of increased intimacy on maize biomass occurred later in the season compared to that of applied N. These results suggest that bean plants contributed N to the associated maize plants, largely from dead and decomposing bean roots and root nodules. The contribution was enhanced by interspecific intimacy.